Believing In God
Believing in God is a matter of faith. It is neither proven or unproven. Instead it is just what people choose to believe or not believe.
People who believe in God are called theists. People who do not believe in God are called atheists.
There are many people in the world and many different religions and beliefs about God. Having different beliefs is OK. Talking about different religions is also OK. Being unkind to someone because of their faith or lack of faith is never OK.
Some people believe in God. This is OK. Some people do not believe in God. This is also OK.
BeING An Atheist
Being an athiest means that you do not believe in God.
People who are atheists often try and find scientific reasons to explain life and everything else in the world and universe. However, science can't always fully explain or prove everything. This means that being an athiest means sometimes just choosing to believe in a scientific theory to explain something. It is OK to be an atheist.
Some people choose not to accept scientific explanations. Instead they believe in God or Gods and may follow a set of beliefs called a religion. There are lots of different religions each with different rules and ideas about life and the universe. It is OK to believe in a religion.
It is OK to be an atheist. But there are also many other ways of explaining the world. If someone believes in a God or Gods this is also OK.